Let's start with the pros. It's cheap. Depending on the day and/or time, you can get out of there fast. Most of the stylists are good. The service is friendly.
This is my biggest issue with Keep It Cut. I ask for the same haircut every visit but the finished product is different every single time! This is mainly because I get a new stylist every time and each one interprets my instructions differently. You can theoretically request a stylist but on a first come, first serve business model, this is just not practical. Do you really want to wait an additional 30-45 minutes for a stylist? Furthermore, their employee turnover seems pretty high so if you find someone you like, they may not be employed there on your next visit.
Bottom line, if you have a simple hairstyle that's difficult to screw up, I would recommend this place in a heartbeat. If you're particular about your hair and need consistency, spend the extra cash and go somewhere else. My last haircut was pretty bad and I may have to take my business elsewhere. Not sure if I can keep 'risking it' every time I need a haircut.
Neat concept but it's not for everyone.